Utilisation rate measures how much of a vehicle’s available time it spends actually earning. It is the heartbeat metric of any rental business: a vehicle that is not rented is capital sitting idle.
The formula
$$\text{Utilisation} = \frac{\text{days rented}}{\text{days available}}$$
A car rented 24 of 30 available days has an 80% utilisation rate. “Available days” normally excludes time the vehicle is legitimately off-fleet — in service or being repaired — so the figure reflects rentable capacity you actually put to work.
Why it matters
Utilisation tells you which vehicles are working and which are dead weight. Consistently low utilisation is a signal to re-price, reallocate or sell a vehicle; consistently high utilisation is a signal to buy more of that type.
The important caveat
Utilisation ignores price. A cheap vehicle rented constantly can earn less than a premium vehicle rented half the time. Always read utilisation alongside revenue per vehicle — utilisation shows how often a vehicle rents, revenue shows how much it earns. Together they drive sound fleet decisions.
Rental reports and analytics calculate utilisation automatically from booking data, which is far more reliable than rebuilding it by hand each month.